Selective blocking device for office typewriter keyboard



April 18, 1961 WLODARCZAK 2,980,228

SELECTIVE BLOCKING DEVICE FOR OFFICE TYPEWRITER KEYBOARD Filed Sept. 26, 1955 INVENTOR AE/V/Z WL 0042C Z 44/( W SELECTIVE BLOCKING DEVICE .FOR OFFICE TYPEWRITER KEYBOARD Heinz Wlodarczak, Plorzheim, Germany, assignor to International Standard Electric Corporation, New York, N.Y., a corporation of Delaware Filed Sept. 26, 1955, Ser. No. 536,601 Claims priority, application Germany Sept. 28, 1954 1 Claim. Cl. 197-107 This invention relates to improvements in perforating typewriters by which a tape may be perforated according to a code, and in particular to improvements in perforating typewriters in which the perforating mechanism may be put-into or out of action as desired.

Perforating typewriters have particular application in preparing perforated tape for printing telegraph purposes. The tape is then stored until a telegraph line is free and the message can be transmitted. Tapeperforated according to the printing telegraph code is frequently used also to control computer apparatus, although other codes may be used for this purpose. In all cases, however, the tape is perforated with a series of holes arranged in a code combination, and a printed record of the message perforated is also obtained.

In order to obtain the maximum efficiency from a perforating typewriter, it is necessary for it to be used for ordinary oiiice correspondence as well as for perforating tape. In the past this has not been possible owing to the fact that the International Teleprinter Code uses the same symbols for letters and for figures, and therefore shift signals have to be inserted before respective sequences of combinations to indicate whether they are letters or figures. No keys are provided on a standard typewriter for these insertions and the only keys available for such function are the standard typewriter case shift keys. The case shift keys then lose their normal function and the typewriter can be used to type either small letters or capital letters, but not both. It is the object of the present invention to provide means by which the typewriter may be adapted for use with a perforator and also be capable of typing both small and capital letters.

It has been chosen to disclose the invention as embodied in a perforating typewriter which may be used in conjunction with a perforating mechanism. When used with the perforating mechanism the usual typewriter left-hand and right-hand case shift keys are utilized separately to perform letter shift and figure shift functions. According to the invention a blocking mechanism is provided, which when operated, responds to the actuation of the left-hand shift key to 'block certain typing keys and permit actuation of others. Similarly, when the right-hand shift key is actuated, the previously blocked keys are freed while the other typing keys are blocked. The keys that are blocked when the one shift .key is actuated may correspond to keys which are to be actuated only when the number shift key is operateddur- 7 ing perforating operations and vice versa. When the blocking mechanism is unoperated, the left-hand and right-hand case shift keys operate as is usual in conventional typewriters, except they are operated independently of each other.

The invention will now be described with reference to the accompanying drawings in which:

Fig. 1 shows a schematic plan view of one embodi 2,980,228 Patented Apr. 18, 1961 with the blocking mechanism in the position shown in Fig. 2A.

Referringv first to Fig. 1, there is shown an ordinary typewriter keyboard, in which the case shift key 1 is to be used as a letter shift key when perforating and the .case shift key 2 as a figure shift key. For this purpose the keys 1 and 2, which are normally coupled together on a typewriter, are arranged to operate independently so that either of them can raise or lower the type basket to print a capital letter without causing the other to be operated at the same time. At the side of the typewriter there is provided a locking handle 10 which is used to bring a locking device into operation when the machine is being used for perforating and to disengage the locking device when the machine is used for typing only. When used for controlling the perforating mechanism, only lower case letters and figures can be typed. The nature and operation of the locking device will be described with reference to Figs. 2a and 3. If the locking hande 10 is rotated in the direction of the arrow shown in Fig. 2 (i.e. anticlockwise), a drawbar 9 is raised. Attached to drawbar 9 is a bar 5 and attached to bar 5 is the locking bar 6, so that the tuming of the locking handle 10 causes bars 5 and 6 to be raised from their lowered, approximately horizontal position as shown in Fig. 2 to an approximately vertical position with respect to the keybars. -The bar 5 (as can be seen in Fig. 3) is pivoted in bearings 7 and 8, which are provided in the side walls ofthe typewriter. Bar 5 cannot, therefore, be moved longitudinally (i.e. in the directions indiacted by the arrows in Fig. 3). The bar 6 however, is fastened to bar 5 in such a way that it can be moved longitudinally, as will be described below.

In the vertical position of bars 5 and 6, the noses of the teeth such as 15 of locking bar 6 lie immediately below the level of the keybars associated with the typewriter keys. The locking handle 10 is conveniently placed at the side of the typewriter and level with the middle of the keyboard. In order that the locking action provided by locking bar 6 shall be effective upon all the keybars of the typewriter, it is necessary for a typewriter key such as 4 in one of the two upper rows of the keyboard to have its associated keybar 18 extended sufiiciently far forward to engage with the locking bar 6 (see Fig. 2).

When the typewriter is being used to operate the perforator, certain keybars have to be locked out of operation. This is done by raising bars 5 and 6 by turningv lock.ng handle 10 as already described. The bars 5 and 6 are now positioned vertically below keybars associated with all the typewriter keys. In order that only predetermined keys can be operated in a given position of bar 6, this bar 6 is provided with teeth such as 15, separated by cut-out portions such as 16. Although only a few such teeth and cut-out portions are shown in Fig. 3 it should be understood that they will appear along the whole operative length of bar 6.

Bar 6 is connected to bar 5 by screws 11 (Fig. 3) through oblong holes 12 in itself so that it may be displaced longitudinally with respect to bar 5, i.e. in either of the directions indicated by the arrows. The movement of bar 6 is controlled by the shift keys 1 and 2 which have beneath them cut-out portions of bar 6 including inclined surfaces 13 and 14 respectively. These 'clusively responsible for the longitudinal movement. a preferred embodiment of the invention, the rotationinclined surfaces-are'so arranged that, in any position of 'bar 6, only one of the shift keys will act on its corresponding inclined surface when depressed.

In Fig. 3, the bar 6 is shown in a position such that the' figure shift key 2 can'bedepresse'd without making 'contact'withany part of bar-6. The -teeth -15 and 'cutouts 16 are then in positions such that certain keys (for example, those keys corresponding to characters in the figures'case of a telegraph code) are above cut-outs such as 16 and can be operated, while the-remaining keys (for example, those keys corresponding tocharacters in the letters case of the telegraph 'code) are above teeth such as 15 and are locked. However, if the letter shift key is depressed'its keybar will impingeon the inclined surface 13 of bar 6 and displace bar 6 to the left. The

teethand cut-outs will then be in a position such that previously locked keys only can be operated. Subsequent'operaiton of figure shift'key 2 will cause its associated keybar to impinge on the inclined surface 14 andcause bar 6 to be moved back to the right tothe position shown when only the last-locked keys can be operated. Operation of either of keys 1 or 2 causes the corresponding letter shift or figure shift combination to be perforated in the tape as well as longitudinally operating the locking device as described.

While it would be possible to use one bar only, instead of the bars 5 and 6 as described, the one bar then being capable of rotational movement and longitudinal movement, it has been found more satisfactory to subdivide the movements so that the bar 5 is exclusively responsible for the rotational movement and bar 6exal'movement of bar 5 under the'control'of locking hanis of-known type) to the typewriter.

While I have described above the principles of my invention in connection with specific apparatus, it is to be clearly understood that this description is made only by way of exampletandrnot as a limitation to the scope of. my, invention .asset forth inthe objects thereof and in the accompanying claim.

What is claimed is:

A mechanical blocking mechanism for use in type- :writer apparatus toconditlon the said apparatus for either of two modes 1 of operation and for selectively conditioningsaid apparatus for either of two kinds of operation within one of said modes, said typewriter apparatus including a first and a second group of typing keys and a first and a second function key, said mechanism including a toothed' bar extending transversely beneath said, groups of typing keys, means for rotating said blocking mechanism between a first position out 'ofengagement withall of said typing keys and a second position in engagement with one of said groups of typing keys, and means controlled by the said function keys when said blocking mechanism is in said second position for laterally moving said toothed bar into engagement with-either of said groups of typing keys.

, References Cited in the file of this patent UNITED STATES PATENTS 

